Two-way radio communications under the best of conditions can be difficult, or at a minimum, problematical. Such communications are often erratic, intermittent, and subject to various forms of environmental and operational interference and disruption. This is particularly true where the elements of the communications system being used are secured within the confines of or upon the structure of a helmet or other type of head gear or head-supported structure. Such helmet-type or head-supported systems are commonly used in military applications involving high-noise conditions in the air such as helicopters and other types of aircraft, on the surface, such as tanks, air-cushion vehicles, and personnel carriers, and on or beneath the surface of a body of water, such as high speed boats, air-cushion watercraft, and submersibles. The above applications, both civilian and military, are not, of course, all inclusive. Likewise, other civilian applications include, but are not limited to, helmets or other head-gear for motorcycle, skydiving, motor boating, jet ski, personal watercraft, firefighting, video game, police work, voice recognition for computers, and hazardous materials applications. There are both civilian and military applications where a gas mask must be worn with a helmet with eye and face protection, without interfering in any way with communications between the user and another.
The environmental exposure to which a helmet or head-supported communication system may be subjected include high and low temperature, extraordinary shock and vibration effects during handling and use, high levels of audible sound, moisture, and toxic and chemically damaging agents. One of the best examples of an environment containing the broadest spectrum of challenging and extreme environmental factors is that of firefighting. The firefighting application demands the use of special apparel such as gloves, helmet liners, and face and eye protective elements that may contribute adversely to the use and operational effectiveness of a helmet communication system.
In existing art helmet or head-supported communications systems, conventional microphones are typically positioned on a boom in front of the user's mouth to pick up speech. In this location, the microphone will pick up ambient background noise including wind noise, breathing, and other external noise transmitted into and through the helmet. Additionally, a boom microphone is obviously subject to physical damage during handling and use by virtue of its exposed and unprotected location. It may also constitute a hazard to the user by virtue of its position near the user's face. If the microphone is of a type mounted directly to the helmet or gas mask, sound and vibrations transmitted through the fabric or material structure will be picked up as interfering noise. Such noise may completely drown out or obscure otherwise intelligible voice communications. Noise cancellation provided by special circuitry may be applied to the microphone output to achieve some degree of improvement.
Speakers used as earphones in helmets or head-supported communications systems are either affixed to the helmet or head-supported structure or placed on the user's head and plugged into an accompanying radio. Typically, in prior art systems, the earphones are not adequately supported and adjustable to provide user comfort, maintainable position, and effective performance in an operationally challenging environment.